mineral

Carnelian

Silicon dioxide / Chalcedony (SiO2)

Hardness: 6.5-7 Mohs; Color: Orange-red to brownish red; Luster: Waxy to vitreous; Crystal Structure: Trigonal (cryptocrystalline); Cleavage: None; Specific Gravity: 2.58-2.64

Hardness: 6
Color: Orange-red to brownish red
Luster: Waxy to vitreous

Identified June 6, 2026More mineral →

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Physical properties

Hardness: 6.5-7 Mohs; Color: Orange-red to brownish red; Luster: Waxy to vitreous; Crystal Structure: Trigonal (cryptocrystalline); Cleavage: None; Specific Gravity: 2.58-2.64

Formation & geological history

Formed through the deposition of silica in groundwater within igneous or sedimentary cavities. The red color comes from iron oxide (hematite) impurities. Commonly found in volcanic rocks.

Uses & applications

Primarily used as a gemstone in jewelry (cabochons, beads), decorative seals, and as a popular specimen for crystal collecting.

Geological facts

Carnelian has been used for over 4,500 years. Ancient Egyptians called it the setting sun and used it in amulets; Romans used carnelian signet rings for sealing wax as the wax does not stick to it.

Field identification & locations

Identify by its translucent waxy appearance and warm reddish-orange color. It is common in India, Brazil, Uruguay, and Madagascar. Collectors often find it in river beds or rocky beaches.